Newt Gingrich may not have been at the Hispanic Leadership Network's Doral conference to listen to Sen. Marco Rubio, but it was clear to the audience here that Gingrich had a tough act to follow, after Rubio gave a sweeping immigration speech.

He repeated many of the U.S. foreign policy themes he laid out Tuesday in a speech at Florida International University but also touched on Puerto Rico, which came up at Thursday night's debate in Jacksonville. At one point, a Puerto Rican woman from the audience interrupted Gingrich to try to get him to say whether he supports statehood for the island.

"I believe the people of Puerto Rico should make that decision," Gingrich said, receiving the most enthusiastic applause of his remarks when he told the woman, "If you don't like it, I disagree."

When he turned to immigration, Gingrich noted the failures of previous Republican and Democratic administrations. "I don't believe you can pass a comprehensive bill," he said, adding that it would face "too many enemies."

"This is where I have a big disagreement with Gov. Romney," Gingrich said regarding what to do with the about 11 million people who are in the United States illegally.

Gingrich, who had mocked Romney's mention of "self-deportation" at a Tampa debate Monday, said "a very significant number" of "young, unattached" undocumented immigrants would go back to their countries and apply for a guest-worker program under Gingrich's porposal. "Self-deportation in fact works for those groups," he admitted.

But not for everyone: "The idea that a grandmother is not going to be supported, the idea that she's going to self-deport...this is not a solution."

Gingrich ended with what he called "a very brief commercial."

"I am running for president," he said, sounding somewhat subdued. "We have a primary here on Tuesday. I'd love to have your support, your endorsement. I'd love you to go on YouTube, Facebook...even talk to people face-to-face.